KR101786638B1

KR101786638B1 - Actuator Unit Of Electronic Parking Brake and Electronic Parking Brake System contain the same, Electronic Parking Brake system control method

Info

Publication number: KR101786638B1
Application number: KR1020160009602A
Authority: KR
Inventors: 노승수; 안대기; 김응수; 강신덕; 송수환; 김대경; 임민철
Original assignee: 이래오토모티브시스템 주식회사
Priority date: 2016-01-26
Filing date: 2016-01-26
Publication date: 2017-10-18
Also published as: KR20170089325A

Abstract

An electronic parking brake system and a control method are disclosed. An electronic parking brake system according to one aspect of the present invention includes a motor, a final gear that rotates at a motor output, a first power coupled to the final gear so as to be axially movable relative to the final gear while being rotated by the final gear, A second power transmitting member that is coupled to the first power transmitting member such that axial movement occurs in response to the rotation of the first power transmitting member, a second power transmitting member that is coupled to the first power transmitting member, A support member fixed at a predetermined position in a state of being opposed to the magnet, an elastic member elastically interposed between the magnet and the support member to elastically support the first power transmitting member in the axial direction, And a Hall sensor spaced apart from the adjacent side of the magnet so as to detect the magnetic force of the magnet, (M is an N or a number of S poles) which is integrally rotatably mounted on an outer surface portion of a first power transmitting member and has N poles and S poles alternately formed in the rotating direction of the first power transmitting member, Pole magnet is used as the essential point of the constitution.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a driving unit of an electronic parking brake, an electronic parking brake system including the driving unit, and an electronic parking brake system control method,

The present invention relates to an electronic parking brake drive unit for providing power for activating or deactivating an electronic parking brake, an electronic parking brake system including the same, and a control method thereof.

Conventional puller type electromagnetic parking brakes include a magnet assembly mounted on one end of a movable shaft constituting a driving unit to measure a tension of a brake cable and a Hall sensor spaced apart from the adjacent side, .

In most cases, the magnet assembly is configured such that it can be mounted on a shaft through a bearing or move like a shaft in a separate form from a bearing so that the magnet assembly moves together with the axial movement of the shaft without rotating during the rotation of the shaft, A spring is mounted.

The spring is compressed when the parking brake is operated, and the parking cable that operates the brake actuating element with its reaction force maintains a predetermined tension. The parking cable is maintained in a taut state by the tension due to the compression of the spring, so that there is no large error in the cable tension measurement by the hall sensor.

However, when the brake is released, the return position of the magnet changes or the tension is excessively removed beyond the tension limit of the spring due to the restoration of the spring tension, so that an error occurs in the measurement of the cable tension by the sensor or the brake cable is excessively loosened there is a problem.

Furthermore, there is a problem that the time required for the parking brake operation or release becomes uneven due to the error in the measurement of the cable tension by the sensor, or the reaction speed is lowered as the brake operation time exceeds the prescribed time. There is a problem that the rear wheel is attracted due to failure to be released completely.

Korean Registered Patent No. 10-1508678 (Registered on March 30, 2015)

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electronic parking brake drive unit having a sensing structure capable of minimizing a measurement error in cable tension measurement, an electronic parking brake system including the same, and a control method thereof .

According to an aspect of the present invention,

motor:

A final gear rotating with the motor output;

A first power transmitting member coupled to the final gear so as to be axially movable relative to the final gear while being rotated by the final gear;

A second power transmitting member coupled to the first power transmitting member such that axial movement occurs corresponding to rotation of the first power transmitting member;

A magnet coupled to an outer surface of the first power transmitting member to move in the axial direction together with the first power transmitting member;

A support member fixed at a predetermined position in a state of facing the magnet;

An elastic member elastically interposed between the magnet and the support member and elastically deformed corresponding to the axial movement of the first power transmitting member; And

And a Hall sensor disposed on an adjacent side of the magnet to detect a magnetic force of the magnet,

The magnet may be an annular two-pole or 2 * M (M is an N or S type) installed rotatably on the outer surface of the first power transmitting member and has N poles and S poles alternately arranged in the rotating direction of the first power transmitting member Number of poles) is provided.

Here, when the parking brake is released, the hall sensor may be disposed on the magnet adjacent side so that the edge of one side of the hall sensor is aligned with the leading edge of the magnet or the center of the magnet coincides with the center of the hall sensor.

According to another aspect of the present invention as a solution to the problem,

A parking brake drive unit according to one aspect;

A controller for deriving a forward / reverse rotation amount of the first power transmitting member from the hall sensor signal of the parking brake driving unit and feedback-controlling the motor by grasping the axial movement distance and position of the first power transmission member from the result of the calculation; And an electronic parking brake system.

Here, the conversion output unit compares the position value of the first power transmitting member, which is detected from the Hall sensor output value, with the previously inputted information, and converts the position value into the tension value of the brake cable connected to the second power transmitting member .

A magnet rotation detecting step of detecting the rotation of the magnet rotating together with the first power transmitting member when the motor is driven through the hall sensor;

A first power transmitting member position grasping step of grasping an axial moving distance and a position of the first power transmitting member in consideration of a screw pitch of the first power transmitting member and the second power transmitting member engaging part from the rotation of the detected magnet; And

A motor stop control step for determining that the parking brake function is started or released when the position value recognized from the rotation amount or the rotation amount of the first power transmitting member reaches the preset value and performing control for stopping the motor The present invention provides a control method of an electronic parking brake system including a parking brake system.

Here, the output value conversion step of comparing the position value of the first power transmitting member, which is detected from the hall sensor output value, with the previously input information and converting the position value into the tension value of the brake cable connected to the second power transmitting member can do.

In the motor stop control step, when the position value recognized from the amount of rotation or the amount of rotation of the first power transmitting member reaches the pre-input set value and it is determined that the parking brake is released, A control may be performed so that the motor is stopped after a further rotation of the transmitting member by a predetermined number of revolutions.

According to the present invention, it is possible to precisely control the position of the first power transmitting member by the sensing structure that minimizes the measurement error in the measurement of the cable tension. Accordingly, when the parking brake is released, It is possible to prevent the brake cable from being loosened and the noise from being generated due to excessive removal of the tension beyond the limit.

Further, by controlling the amount of rotation of the first power transmitting member (shaft) to implement the parking brake actuation / disengagement, compared with the conventional manner in which the brake operation is controlled only by the axial movement distance of the first power transmitting member, So that the overall reliability of the parking brake system can be further improved.

Particularly, since the amount of axial movement of the first power transmitting member can be more accurately and finely controlled by the amount of rotation control, the time taken to operate or release the parking brake becomes uneven, or the brake operation time exceeds the prescribed time And the release of the incomplete parking brake due to the detection error and the subsequent rear wheel dragging phenomenon can reliably be solved.

1 is a side view of an electronic parking brake drive unit according to an aspect of the present invention;
Fig. 2 is an enlarged view of the essential part of the present invention showing the positional relationship between the magnet and the Hall sensor in Fig. 1 and a preferred embodiment of the magnet. Fig.
Fig. 3 is an output diagram showing a change in output of the hall sensor over time when the magnet is rotated. Fig.
4 is a schematic view of an electronic parking brake system according to another aspect of the present invention including the above-described electronic parking brake driving unit of the present invention.
Fig. 5 is a block diagram sequentially showing a parking brake control process performed through the electronic parking brake system of Fig. 4; Fig.

Hereinafter, preferred embodiments of the present invention will be described in detail.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. It is to be understood that the terms "comprises", "having", and the like in the specification are intended to specify the presence of stated features, integers, steps, operations, elements, parts or combinations thereof, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, parts, or combinations thereof.

Also, the terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

In addition, the terms " part, "" unit," " module, "and the like, which are described in the specification, refer to a unit for processing at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software .

In the following description with reference to the accompanying drawings, the same reference numerals are given to the same constituent elements, and a duplicate description thereof will be omitted. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

1 is a side view of an electronic parking brake drive unit according to a first embodiment of the present invention.

Referring to Fig. 1, the drive unit of the electronic parking brake includes a motor 10. The motor 10 may be operated with a control signal for activating or deactivating the electronic parking brake and the control signal may be transmitted to the controller in accordance with the operation of turning on or off the parking brake operation switch which can be installed at an appropriate position around the driver's seat Lt; / RTI >

The rotational power of the motor 10 is converted to linear motion in the middle and finally transmitted to the brake cable 100. That is, the brake cable 100 is pushed or pulled by the power output from the motor 10. At this time, the brake cable 100 is connected to the operating element of the parking brake, and by the movement of the brake cable 100, the parking brake operating element can be actuated and the parking brake can be operated or released.

The rotational power output by the motor 10 is transmitted to the final gear 30 via the driving gear 20 and the final gear 30 is coupled to the first power transmitting member 40. The first power transmitting member 40 may be implemented in the form of a shaft and is rotatable with the final gear 30 by the power of the motor 10 transmitted through the driving gear 20, And is coupled to the final gear 30 to enable axial movement.

In other words, the final gear 30 does not move in the axial direction during rotation, but the first power transmitting member 40 is provided so as to be able to move relative to the final gear 30 in the axial direction. To this end, corresponding protrusions (not shown) and recesses (not shown) are formed on the outer surface of the first power transmitting member 40 and the inner surface of the final gear 30, to which the final gear 30 is engaged, .

The second power transmitting member 50 is fastened to the first power transmitting member 40 and the brake cable 100 is connected to the second power transmitting member 50. [ The first power transmitting member 40 and the second power transmitting member 50 are connected to each other by a screw thread that can be engaged with each other so that the two members are screwed to each other, 1 and the second power transmitting members 40, 50 are overlapped with each other or moved in the opposite axial direction.

That is, when the first power transmitting member 40 rotates, the second power transmitting member 50 is moved in the axial direction corresponding to the rotation of the first power transmitting member 40, The parking brake is operated or released. Of course, in correspondence with the axial movement of the second power transmitting member 50, the first power transmitting member also rotates together with the rotation in the axial direction.

One end portion 47 of the first power transmitting member 40 may be formed in a hollow structure having a threaded portion formed on the inner circumferential surface thereof for screw engagement of the first and second power transmitting members 40 and 50, 2 power transmission member 50 may have a configuration in which a thread 51 of a pitch PITCH that is in mesh with the threads of the first power transmitting member 40 is formed on the outer peripheral surface in the form of a spindle shaft.

The second power transmitting member 50 is inserted into the hollow portion of the first power transmitting member 40 in a state in which the thread 51 is fastened to the thread of the first power transmitting member 40. [ The second power transmission member 50 has a connecting portion 53 to which the brake cable 100 is connected at an end of the second power transmitting member 50 connected to the first power transmitting member 40, And only the axial movement is allowed.

A magnet 60 is coupled to the first power transmitting member 40 so as to be axially movable together and a support member 70 provided to face the magnet 60 is fixed at a predetermined position. The magnet 60 is moved in the axial direction together with the first power transmitting member 40 and the supporting member 70 is fixed at a designated position regardless of the movement of the first power transmitting member 40. [

Although not shown in the drawing, the support member 70 can be fixed to the step formed on the case. The magnet 60 and the support member 70 may be formed in the form of a substantially annular plate having a hole at the center thereof and the first power transmitting member 40 is installed so as to pass through the center portion thereof. At this time, the magnet 60 may be fixed to the first power transmitting member 40 so as to be axially moved while rotating together with the first power transmitting member 40.

An elastic member (80) is provided between the magnet (60) and the support member (70). The elastic member 80 elastically compresses or restores between the magnet 60 and the supporting member 70 in accordance with the axial movement of the first power transmitting member 40, thereby moving the first power transmitting member 40 in the axial direction And serves to substantially form a tension on the brake cable 100 in response to the displacement.

The elastic member 80 is elastically deformed between the magnet 60 and the support member 70 in accordance with the axial movement of the first power transmitting member 40 so that a predetermined tension is applied to the brake cable 100 So that the brake cable 100 maintains a tight tension at all times between the parking brake operating position and the release position although the magnitude of the tension is different.

The elastic member 80 may be a coil compression spring, for example, as shown in the drawing, and both ends of the coil spring may be supported by the magnet and the support members 60 and 70. An intermediate medium 85 such as a bush or a thrust bearing may be interposed between the magnet 60 and the coil spring so that the coil spring does not rotate even if the magnet 60 rotates.

A sensor, preferably a hall sensor 90, which is operated by the magnetic force of the magnet 60, is provided on the adjacent side of the magnet 60. 2, the magnet 60 is formed of an annular two-pole or 2 * M (M is an N or S pole having an N pole and an S pole alternately formed in the rotating direction of the first power transmitting member 40 And the Hall sensor 90 may be mounted to face the magnet 60 on the PCB 110 fixed to the case (not shown).

The Hall sensor 90 senses the rotation and the axial movement of the magnet 60 rotating together with the first power transmitting member 40 when the motor 10 is driven and the magnet 90 and the axial position, that is, the rotation amount of the first power transmitting member 40 and the axial position, information on the operation of the parking brake and the braking force can be obtained.

FIG. 2 is an enlarged view of the essential part of the present invention showing the positional relationship between the magnet and the Hall sensor in FIG. 1 and a preferred embodiment of the magnet.

2, when the parking brake is released, the hall sensor 90 may be disposed on the magnet adjacent side so that one edge of the hall sensor 90 is aligned with the leading edge of the magnet 60. In this way, the amount of rotation of the first power transmitting member 40 and the axial momentum corresponding thereto can be accurately obtained when the parking brake is operated or released, and more accurate position control can be performed.

Of course, the hall sensor 90 may be disposed on the side adjacent to the magnet 60 so that the center of the magnet 60 and the center of the hall sensor 90 coincide with each other, though not specifically illustrated in the drawings.

FIG. 3 is an output diagram showing changes in output of the Hall sensor over time when the magnet is rotated. In the case of using a two-pole magnet having N poles and S poles alternately arranged at a pitch of 180 degrees, Fig.

In the waveform signal of Fig. 3, a floor, a floor or a space between the valley and the valley means one rotation of the magnet 60 and the first power transmitting member 40, The convex signal is the output (V) of the Hall sensor 90 when the N pole is sensed and the signal output in the downward convex form indicates the output change of the Hall sensor 90 when the S pole is sensed.

The rotation amount of the first power transmitting member 40 can be known from the cycle of the output change of the hall sensor 90 which is shaped like the one shown in Fig. 3 in accordance with the rotation of the magnet 60, The axial movement distance of the first power transmitting member 40 from the output signal of the hall sensor 90 can be determined from the pitch of the thread of the first power transmitting member 40 The moving amount can be grasped accurately.

3 (a) and 3 (b) according to the relative positions (X ₀ , X ₁ , the axial position of the magnet visible through the magnet rotation number) of the magnet 60 with respect to the Hall sensor 90 the relative position of the magnet 60 with respect to the hall sensor 90 is determined only by the bias voltage included in the output of the Hall sensor 90. That is, The axial position of the member 40 can be accurately grasped.

An electronic parking brake system according to another aspect of the present invention will now be described.

4 is a schematic view of an electronic parking brake system according to another aspect of the present invention including the above-described electronic parking brake driving unit of the present invention.

Referring to Fig. 4, the electronic parking brake system according to another aspect includes a control section 2 for feedback-controlling the parking brake drive unit 1 and the parking brake drive unit 1. [ The parking brake drive unit 1 is the same as the aforementioned one drive unit 1 and the control unit 2 controls the drive unit 1 based on the Hall sensor 90 signal of the parking brake drive unit 1. [ The motor 10 of FIG.

Specifically, the control unit 2 accurately derives the forward / reverse rotation amount of the first power transmitting member 40 from the output of the Hall sensor 90, which changes in accordance with the rotation of the magnet 60, And the motor 10 is feedback-controlled by grasping the axial movement distance and the position of the transmitting member 40.

The rotation amount and the position value of the first power transmitting member 40 that are grasped from the amount of rotation of the magnet 60 are set to a preset value, for example, an output value according to the position of the magnet 60 at the start or release of the parking brake The control unit 2 determines that the parking brake function is started or released and performs control for stopping the motor 10 so that the parking brake driving unit 1 is stopped.

The position value of the first power transmitting member 40, which is grasped from the output value of the hall sensor 90, can be converted and outputted to the tension value caught by the brake cable by the conversion output section. The conversion output unit converts the tension information of the brake cable, which is input in advance in correspondence with the position value of the first power transmitting member 40, into a tension value by using data arranged in a table form through a preliminary simulation .

Of course, a predetermined relation between the position value of the first power transmitting member 40 and the tension value of the cable is derived by using the data through the repeated experiment or the pre-simulation, and the output value of the hall sensor All the methods that can be practically derived, including calculating and outputting the tension value automatically applied to the brake cable, can be considered.

FIG. 5 is a block diagram sequentially illustrating a parking brake control process performed through the electronic parking brake system of FIG. 4;

Referring to FIG. 5 and FIG. 4, when the motor 10 of the parking brake driving unit rotates by inputting a parking brake actuation command or an unlocking command by the driver, when the motor 10 is driven by the hall sensor, The rotation of the magnet 60 rotating together with the transmitting member 40 is detected (magnet rotation detection step S100), and the detected rotation related information of the magnet 60 is transmitted to the control unit 2 in a predetermined electrical signal form do.

The control unit 2 derives the accurate amount of rotation of the magnet 60 and the first power transmitting member 40 coupled with the magnet 60 from the Hall sensor output that changes in accordance with the rotation of the magnet 60, The accurate axial movement distance and position of the first power transmitting member 40 are calculated in consideration of the amount of rotation of the first power transmitting member 40 and the thread pitch of the second power transmitting member engaging portion 40 Power transmission member position determination step S200).

If it is determined that the parking brake function is started or released when the position value recognized from the amount of rotation or the amount of rotation of the first power transmitting member 40 reaches the pre-input set value, the controller 2 stops the motor 10 (The motor stop control step, S300). At this time, the position value of the first power transmitting member 40, which is grasped from the output value of the Hall sensor 90, can be converted and outputted as a tension value applied to the brake cable (Output value conversion step, S250).

On the other hand, when the position value recognized from the amount of rotation or the amount of rotation of the first power transmitting member 40 reaches the pre-input set value and is determined to be a parking brake release, If the motor 10 is set to stop after the motor 40 is further rotated by the predetermined number of revolutions, the parking brake release can be more reliably realized and the brake cable tension can be prevented from being excessively removed.

The detection signal of the magnet 60 outputted by the hall sensor 90 may be divided into AC component and DC component value through circuit elements or software elements, respectively. In this case, the first power transmission member 40, And the position information of the first power transmitting member 40 can be read from the DC component, so that it is possible to grasp the amount of rotation and the position information at the same time more quickly.

In the foregoing detailed description of the present invention, only specific embodiments thereof have been described. It is to be understood, however, that the invention is not to be limited to the specific forms thereof, which are to be considered as being limited to the specific embodiments, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. .

10: Motor 20:
30: final gear 40: first power transmitting member
50: second power transmitting member 60: magnet
70: support member 80: elastic member
90: Hall sensor 100: Brake cable

Claims

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A first power transmitting member that is coupled to the final gear so as to be capable of axial relative movement with respect to the final gear while being rotated by the final gear; A second power transmitting member that is coupled to the first power transmitting member so that axial movement occurs, a second power transmitting member that is coupled to an outer surface of the first power transmitting member to move in the axial direction together with the first power transmitting member, An annular magnet having N poles and S poles alternately formed in the direction of rotation of the transmitting member; a support member fixed at a predetermined position in a state of facing the magnet; and a resilient member elastically interposed between the magnet and the support member, An elastic member which is elastically deformed corresponding to the axial movement of the transmitting member, and an elastic member which is disposed apart from the adjacent side of the magnet so as to detect the magnetic force of the magnet Parking brake driving unit including a sensor; And
The amount of forward / reverse rotation of the first power transmitting member is derived from the hall sensor signal of the parking brake driving unit, and the axial movement distance and position of the first power transmitting member are grasped from the result of the calculation, And a control unit,
The magnet detection signal by the Hall sensor is converted into a value of a DC component providing an AC component providing information on the amount of rotation of the first power transmitting member and a position information of the first power transmitting member through the circuit element or the software element,
When the position value recognized from the amount of rotation or the amount of rotation of the first power transmitting member reaches a preset value and is determined to be a parking brake release, the control unit controls the first power transmitting member And stops the motor after a predetermined number of turns of the parking brake system.

The method of claim 3,
And a conversion output unit for comparing the position value of the first power transmitting member, which is obtained from the Hall sensor output value, with the previously inputted information, and converting the position value into a tension value of the brake cable connected to the second power transmitting member, Electronic parking brake system.

A magnet rotation detecting step of detecting the rotation of the magnet rotating together with the first power transmitting member when the motor is driven through the hall sensor;
A first power transmitting member position grasping step of grasping an axial moving distance and a position of the first power transmitting member in consideration of a screw pitch of the first power transmitting member and the second power transmitting member engaging part from the rotation of the detected magnet; And
A motor stop control step for determining that the parking brake function is started or released when the position value recognized from the rotation amount or the rotation amount of the first power transmitting member reaches the preset value and performing control for stopping the motor &Lt; / RTI >
Wherein the magnet detection signal by the hall sensor in the magnet rotation detection step includes an AC component providing information on the amount of rotation of the first power transmitting member through a circuit element or a software element and a DC component providing position information of the first power transmitting member , &Lt; / RTI >
In the motor stop control step, when the position value recognized from the amount of rotation or the amount of rotation of the first power transmitting member reaches the pre-input set value and it is determined that the parking brake is released, Wherein the motor is stopped after the motor is further rotated by a predetermined number of revolutions.

6. The method of claim 5,
And an output value converting step of comparing the position value of the first power transmitting member, which is grasped from the hall sensor output value, with the previously inputted information and converting the position value into a tension value of the brake cable connected to the second power transmitting member Control method of parking brake system.

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